Cow comfort — summer field days and snippets from around the world
The recently completed 2011 University of Minnesota Successful Dairy Systems Field Days, which focused on "Cow Comfort", were held on 11 dairy farms in various locations in the state. During our first full week in mid-July, we 'enjoyed' temperatures in the high 90s with heat indexes in the low 100s. It was a tough time for cows and people! It certainly emphasized the importance of heat abatement in the summer. The dairy farms hosting the field days were managing their herd well under the circumstances. They were using sprinklers and fans to cool their cows. A considerable amount of water was being used during that week just to cool the cows down. On dairy farms, daily production per cow was certainly being affected but the main objective was to keep cows healthy and alive. Yes, this type of weather is stressful! But, in spite of it, around 500 dedicated folks attended our field days. Participants learned from what they saw at these dairy operations and from the host producers who are providing good cow comfort for their animals.
Prevention of lameness was one management area I discussed during the field days. Many aspects of cow comfort have been shown to be associated with lameness. Heat abatement is one of them, a topic I have previously written an article on entitled, "Be ready for summer!" (http://www1.extension.umn.edu/dairy/facilities/be-ready-for-summer/index.html). Information was also presented on surface and stall design as research has shown that deep beds provide cows with better cushion and traction, therefore reducing lameness prevalence. Recent research we have conducted using recycled manure solids for bedding also showed that herds with deep beds had lower lameness prevalence than herds with mattresses. However, the difference was less than what previous studies had shown when comparing sand and mattresses because with recycled solids, more bedding is used on top of the mattress.
Another important area for lameness prevention is housing and management during the transition period. Cows need to be provided with enough resting space (preferably 10% more stalls than cows) and feed bunk space (30 inches per cow) during this critical period. Some producers are using a bedded pack for their special needs animals (close-up, fresh cows, lame cows) that can also help reduce lameness prevalence.
Flooring surfaces are very important for all cows. Special emphasis should be placed on adequate grooving of concrete floors with no severe imperfections that could cause injury. The use of rubber flooring in the holding pen, parlor and return alleys could possibly be considered. Hoof trimming every cow at least once a year can also reduce lameness. Make sure your hoof trimmer is well trained and uses appropriate technique.
The easiest aspect of management shown to be correlated with lameness is cow handling. Move cows slowly and quietly to and from the parlor and when sorting. Keep them away from resting spaces for less than 1 hour per day (for health checks, treatments, breeding, or other management practices). All will make a difference in cow health and productivity.
- A recent study in Finland showed that cows sleep for about 5 hours per day and have REM (rapid eye movement) sleep for 45 minutes per day in bouts of about 5 minutes. For some time they are also in a state of 'drowsiness' especially when ruminating and resting. Cows need to have adequate resting surfaces and space to perform these behaviors.
- A study at University of California-Davis demonstrated that cows preferred feed bunks with sprinklers both at feeding (69 vs. 34% of the time) and when standing without feeding (84.5 vs. 15.5% of the time) compared to feed bunks that had shade but no sprinklers.
- An on-farm study conducted by the University of British Columbia in California, NE U.S. (New York, Pennsylvania, Vermont) and British Columbia found that prevalence of lameness was 31, 55, and 28%, respectively. Prevalence of hock lesions was 56, 81, and 41%, respectively. The variation in lying time was positively associated with lameness prevalence.
- Our University of Minnesota study evaluated the sample size needed to accurately estimate outcome-based measurements of dairy welfare during herd evaluations. We found that at least 15% of the group needs to be scored to estimate lameness prevalence and at least 30% to estimate severe lameness or severe hock lesion prevalence.
- Canadian studies have shown that the automated assessment of lameness on farms, such as using accelerometers, has potential. It was suggested that a combination of technologies into one system would be the most useful to help detect hoof problems early.
These are just some examples of studies taking place. It is good to see interest and research on dairy cattle welfare expanding in the U.S. and abroad! The dairy industry as a whole will benefit.